Abstract
For the cancer imaging therapy the development of appropriate drugs has been carried out actively. Cu-PTSM is a kind of drug which was made in the development work. Cu-PTSM is not incorporated selectively only to cancer cells but it is known that the accumulation ratio in cancer cells is very high. In this study Cu-PTSM was incorporated to tumor cells, then the cells were irradiated with monochromatic X rays having energy around Cu-K edge at KEK-PF. The radiation energy of the monochromatic Cu-K X rays should be absorbed at Cu atom selectively and the special effect should be expected through the photo-electric effect in Cu atoms. In this study chromosomal aberrations, especially isochromatid breaks, were measured as radiation effect. The energy of the monochromatic X rays used for the experiments were 8.944 keV (Cu-K lower) and 9.034 keV (Cu-K higher). As a result, the induction of isochromatid breaks were clearly shown in the both cases of Cu-K lower and Cu-K higher irradiation depending linearly on the concentration of Cu-PTSM involving in U2OS cells. In the case of irradiation with Cu-K higher X rays at 500 nM Cu-PTSM concentration, the yield of isochromatid breaks was 1.8 times larger than that with Cu-K lower X rays.
